Direct myocardial revascularization (DMR), also referred to as percutaneous myocardial revascularization, is a technique that allows physicians to treat patients who have sustained a myocardial infraction by burning channels in the myocardium that has been determined to be ischemic heart tissue. The channels, which are burned by a laser, allow for angiogenesis, i.e., the formation of blood vessels.
Several myocardial revascularization procedures are known that require that the chest wall be opened to access the heart muscle with laser devices. The procedures are not very desirable, as they require major surgery that can result in severe complications. Aita et al., U.S. Pat. No. 5,389,096, describes a procedure for performing myocardial revascularization percutaneously by inserting a guidable elongated flexible lasing apparatus, such as a catheter, into a patient's vasculature. The distal end of the catheter is guided to an area in the heart to be revascularized. The inner wall of the heart is then irradiated with laser energy to cause a channel to be formed from the endocardium into the myocardium.
For obvious reasons, DMR catheters require the physician to have more control and information than other catheters having an optic fiber, such as ablation catheters. Aita et al. generally describes a DMR catheter. The present invention is directed to an improved DMR catheter which allows the physician to have greater control and obtain more information than the catheter described in Aita el al.